1. Field of the Invention
This invention relates to erosion control systems, and more particularly, to erosion control systems which include primary elements having truncated conical recesses for receiving articulated interconnect links having only first and second ends.
2. Description of the Prior Art
In many environments, it is highly advantageous to protect the surface of an area of soil from erosion due to either wind or water flow. A variety of erosion control systems have been designed primarily for the purpose of preventing soil erosion on the beds and banks of dikes, canals, and rivers or to preserve beaches. Cost, ease of fabrication and installation and overall effectiveness of these erosion control systems each represent significant considerations.
Erco Systems, Inc. of Jefferson, La. has designed and marketed a Tri-lock erosion control system which includes two triangular-shaped interlocking elements. The first triangular-shaped element includes circular end sections for interlocking with cylindrical apertures within a second triangular-shaped element. A plurality of these first and second elements are interlocked to form an erosion control mat. A filter cloth is positioned below this mat and forms a part of the Erco erosion control system. Erco Systems, Inc. also markets another erosion control system including a plurality of blocks of various different configurations which are coupled to a fabric filter cloth for the purpose of preventing soil erosion caused by water flow. Erco Systems markets yet another erosion control system referred to as the TERRAFIX Channel Lining System. This system is fabricated from a plurality of rectangular blocks including horizontally oriented projections on the upper surface. These horizontally oriented projections interlock with corresponding horizontally oriented apertures in the lower surface of adjacent blocks to form a flexible, unitary erosion control system.
Certain types of erosion control systems are also commonly referred to as revetments. Swiss Pat. No. 93,186 (Blanchod) discloses a revetment fabricated from a plurality of substantially rectangular blocks including cylindrical recesses in the end sections of each block. A link having first and second substantially cylindrical end sections fits within the cylindrical recesses in the ends of the adjacent blocks to maintain a fixed distance between adjacent blocks. The Blanchod patent fails to disclose any means for maintaining a fixed distance between adjacent rows of blocks which may be utilized in a revetment.
U.S. Pat. Nos. 2,502,757 (Shearer); 2,454,292 (Pickett); 2,008,866 (Hoffard) and 1,847,852 (Upson) disclose revetment mats which include a plurality of elements typically fabricated from concrete and interconnected by various types of cables or steel links.
U.S. Pat. Nos. 4,152,875; 2,876,628; and 1,983,772 disclose another general type of articulated revetment mat formed from somewhat larger sections of concrete blocks connected by steel links. U.S. Pat. Nos. 3,990,247; 2,159,685; and 1,993,217 disclose revetments formed by placing multiple layers of materials above a bank or river bed.
U.S. Pat. No. 3,903,702 discloses a revetment fabricated from a plurality of interlocking concrete blocks. U.S. Pat. No. 3,922,865 discloses a revetment formed from a plurality of concrete blocks which are secured to an underlying cloth mat.
The following U.S. Patents disclose various other types of erosion control systems: U.S. Pat. Nos. 4,227,829; 4,139,319; 3,597,928; 3,947,190; and 1,179,121.